The 1 mm resolution is so stable, that when measuring typical objects at
a distance of one meter, the readings do not change by more than 1 mm.
The best stability is available with the TTL and RS232 serial outputs
with a typical error of
± 0.1% at one meter. The pulse width has a stability of
±
0.2 %, while the rail to rail analog voltage output has a resolution of
5 mm.

Most low cost ultrasonic rangefinders will report the range to smaller
size targets as farther than the actual distance. In addition, they will
also report the range to larger size targets as closer than the actual
distance. The HRLV-MaxSonar-EZ sensor line correctly compensates for
target size differences. This means that, if an object is large enough
to be detected, the sensor will report the same distance regardless of
target size.

Most low cost ultrasonic rangefinders will report
the range to smaller size targets as farther than the actual distance. In
addition, they will also report the range to larger size targets as closer than
the actual distance. The HRLV-MaxSonar-EZ sensor line correctly compensates for
target size differences. This means that, if an object is large enough to be
detected, the sensor will report the same distance regardless of target size.

Other ultrasonic rangefinders will fail when used
with other ultrasonic sensors nearby. By comparison, the HRLV-MaxSonar-EZ
sensors can be used with other sensors in close proximity. Other nearby
ultrasonic sensors will have little to no affect on the reported range of the
HRLV-MaxSonar-EZ sensors. The noise filtering of the HRLV-MaxSonar-EZ is now
even better than the previous MaxSonar products, and will work in the presence
of many more noise sources and outside noise sources with higher amplitudes.
Most range readings are accurately reported, but if the range readings are
affected, the effect is typically less than 2 cm.

The HRLV-MaxSonar-EZ sensor allows for accurate
temperature compensation. The speed of sound changes up to 0.6% per degree
centigrade. To compensate for this effect the sensor must monitor the changes to
air temperature, while ignoring self-heating. Self-heating is an issue with
internal temperature sensors, where the temperature increase is typically 2 to 5
degrees centigrade. If ignored, this will cause a drift of the reported range of
up to 3%. Alternatively, when using an external temperature sensor, it will not
be affected by self-heating of the main sensor electronics. The HR-MaxTemp is an
external temperature sensor that can be easily connected to an HRLV-MaxSonar
sensor. Once connected, the HRLV-MaxSonar sensor will auto detect the presence
of the external temperature sensor, and it will accurately compensate for
temperature effects. The HR-MaxTemp is available as an option as an
non-assembled kit for $4.95 (MSRP).

The HRLV-MaxSonar-EZ comes with the easy to use
outputs and standard pin configuration of the previous MaxSonar products. In
addition to the three standard sensor outputs of RS232 serial, Analog Voltage,
and Pulse Width, there is now a user selectable TTL serial output.

Similar ultrasonic products may have frequent side
lobe detection and can even falsely trigger on objects behind or to the sides of
the sensor. The HRLV-MaxSonar-EZ offers a controlled beam that is designed to
reject small objects (clutter) outside of the central beam area and provides a
long range sensitivity without detecting frivolous or unwanted targets. The
HRLV-MaxSonar-EZ is 100% factory calibrated and tested before it is bagged and
shipped. This ensures proper sensor operation and consistent performance from
sensor to sensor.

The final assembly is a small unit less than 1 cubic
inch, weighs 4.3 grams, and operates from 3 V to 5 V.